Tunable car vibrator



2 Sheets-Sheet 1 Filed Feb. 15, 1960 INVENTOR.

ALBERT MUSSCHOOT ATTORNEY y 1964 A. MusscHooT 3,133,652

TUNABLE CAR VIBRATOR INVENTOR. ALBERT MUSSCHOOT ATTORNE United States Patent 3,133,652 TUNABLE CAR VIBRATQR Albert Musschoot, Anchorage, Kym, assignor to Chain Belt Company, Milwaukee, Win, a corporation of Wisconsin.

Filed Feb. 15, 1960, Ser. No. 3,846 4 Claims. (Cl. 214-835) This invention relates to vibratory apparatus and in particular to a tunable, portable vibrator adapted to be attached to the side frames of railroad hopper cars and similar containers for vibrating such containers to accelerate the discharge of the contents thereof.

Vibrators of various forms have been employed to accelerate the discharge from containers of various forms such as railroad hopper or grain cars or similar containers. One of the ditficulties encountered when using such vibrators is the damage that often occurs at the point of contact between the vibrator and the container when the vibrator is operated at sufficiently high amplitudes of vibration to produce the desired vibratory action in the container. Another disadvantage of the known types of portable vibratory equipment for use with railroad hopper cars or similar containers is the large size of vibratory drive unit that is required to produce an adequate amplitude of vibration to facilitate the discharge of material.

The principal object of this invention is to provide a portable car vibrator that may be tuned while in operation to adjust its resonant frequency to the speed of operation and thus produce a very vigorous vibratory motion without requiring heavy eccentric weights or heavy vibratory apparatus.

Another object of the invention is to provide a light weight vibration generator, which by resonant operation, produces large vibratory force at frequencies suitable for vibrating the sides of a hopper car or similar container.

More specific objects and advantages are apparent from the following description of a preferred form of the invention.

According to the invention the improved vibrator comprises a frame containing integral clamping means for attaching the frame to a side rail of a railroad car or similar apparatus and a vibration exciter resiliently coupled to the frame to form a tuned vibratory system in which the resilient coupling elements are adjustable in rate to permit ready tuning of the apparatus to resonance regardless of the usual variations and characteristics of the railroad cars or hopper cars to which the apparatus may be applied.

A preferred form of the invention is illustrated in the accompanying drawings.

In the drawings:

FIG. I is a fragmentary elevation showing a fragment of a railroad hopper car with the improved vibrator attached thereto.

FIG. II is an enlarged side elevation of the improved vibrator.

FIG. III is a fragmentary section taken substantially along the line IIIIII of FIG. 11.

FIG. IV is a plan View of the improved vibrator assembly.

FIG. V is a vertical section taken substantially along the line VV of FIG. IV showing the vibrator clamped to a sill member of the car.

3,133,652 Patented May 19, I964 FIG. V1 is a schematic piping diagram showing the connections from a supply line to the various flexible walled chambers or air springs making up the resilient elements of the assembly.

These specific figures and the accompanying description are intended merely to illustrate the invention and not to impose limitations on its scope.

The improved vibrator is adapted to clamp onto a side rail 10 of a hopper car 11 (FIG. I) or similar container and apply laterally directed vibration exciting force thereto at an amplitude sufficient to dislodge materials from the Wall of the hopper and facilitate discharge of the material through the bottom of the car. As illustrated, the fragment of the car includes the side wall 12, the sill or side rail 10, and one wheel 13 of one truck of the car arranged to run on a rail 14 in the usual well known manner. In the ordinary discharge arrangement the hopper car is positioned over a pit and the space between the rail 14 and the adjacent side of the pit is covered with a grating 15.

The improved vibrator comprises a vibration generator assembly 2%) which is ordinarily supported on a flexible cable 21 so as to be freely movable to and from its engaged position with the side of the car. The improved vibration generator, as seen in considerable detail in FIGS. II, III, IV and V, comprises a main frame 25 having a longitudinally extending rib 26 attached to its upper surface and extending upwardly therefrom to pro vide a connection for a clevis or hook 27 that is hooked into a hole 23 in the rib 26. The vibrator assembly 23 also includes a yoke 30 having side rails 31 and 32 that slidingly embrace the vibrator frame 25 and that on their forward ends carry a jaw 33 adapted to cooperate with a front face 34 of the frame 25 to provide a clamp that engages the side rail 10 of the hopper car.

At its opposite end the yoke 30 includes a cross tie 35 which is securely braced by side gusset plates 36 to withstand the force exerted by a flexible side wall air cylinder 37 interposed between the cross member 35 and an adjacent face 38 of the frame 25. The expansible chamber 37 constitutes a force supplying means for sliding the yoke 30 relative to the frame 25 so as to close the clamping jaws 33 and 34 on the car frame member.

The side arms 31 of the yoke 39 are guided at the forward end of the frame 25 between spaced opposing faces of short lengths of angle iron 40 and 41 attached to the frame 25 and which together provide a short guide way. At the rear end of the frame 25, adjacent the face 38, a laterally extending lip 42 of an angle iron bracket 43 is engaged between the lower surface of the side rails 31 or 32 and a short length of angle iron 45 that is slightly spaced from and bolted to the underside of the side rail 31. Preferably the side rails 31 and 32 are channel irons to get as strong a yoke as possible with a minimum weight.

A vibration exciter 50 is mounted in the frame 25 by means of a plurality of guide links 51 that are pivotally connected, as by rubber bushings, to upper support bolts 52 fixed in side walls of the frame 25 and to lower guide bolts 53 fixed in the side walls of the exciter member 53. These guide links 51 permit relative motion between the exciter frame 50 and the main frame 25 along a direcarse s52 Relative motion along this path is resiliently resisted by a pair of flexible side wall, expansible chambers 55 and 56 that are interposed between adjacent facing surfaces of the box-like outer frame 25 and the exciter member 50. The flexible side wall expansible chambers 55 and 56 are preferably similar in design to the air springs used in some automotive vehicles. These cxpansible chambers, serving as springs, have the desirable characteristic that their spring rates can be adjusted by varying the gas or air pressure in the chambers.

Since the pair of chambers 55 and 56 act in opposition to each other insofar as static force is concerned, and they each push on the exciter 51 in the frame 25 with a force that varies according to their individual deflections, it follows that the total resilient force tending to return the exciter 50 to its midposition is equal to the movement of the exciter member 54) from its midposition multiplied by the sum of the spring rates of the pair of resilient chambers 55 and 56. Actually, because of the inverse relation of pressure and volume in a confined gas, the spring rate of the chambers 55 and 56 is not linear. However, the use of pairs of springs acting in opposition tends to cancel out most of the nonlinearity so that over the operating range the combination of two springs exhibits a nearly constant spring rate which varies according to the average pressure of the gas in the chambers.

Air pressure is supplied to the expansible chambers 55 and 56 as well as to the yoke operating expansible chamber 37 by way of an air line 66 which, as shown in FIG. V, may be clamped to the support cable 21 and which leads to a control box 61 fitted with a pair of valves 62 and 63 which in turn are controlled by knobs or handles 64, 65. The valve 63 is shown in FIG. VI as being two separate valves inasmuch as it must be the equivalent of a 3 way type which can release the pres sure in the chambers to reduce the spring rate or clamping pressure when so required.

In the operation of this assembly the vibrator 2t? is maneuvered into engagement with the side rail lltl of the car located between the faces 33 and 34 of the clamping portion of the mechanism and then the valve 62. controlled by handle 64 is opened to allow air to flow into the chamber 37 and thus slide the yoke relative to the frame 25 to tighten the jaw faces 33 and 34 against this side rail. This pressure is maintained throughout the operation of the device to hold the clamping jaws securely in place. Once the vibrator is clamped in place electrical power is supplied through a cable 70 to an electric motor 71 mounted in the vibration exciter 50. The motor 71 has an armature shaft 72 that carries eccentric weight 73 on each end. When power is supplied to the motor, which preferably is a constant speed motor, it comes up to speed and the force of the unbalanced weights 73 is applied through the armature shaft and the motor to the exciter member 50. The air pressure in the expansible chambers or air springs 55 and 56 is then adjusted by manipulation of the valve 63 so that the vibratory system composed of the side of the car 11 with the weight of the frame 25 as one member and the exciter member as the second member forms with the resilient members or air springs 55 and 56 a vibratory system having a natural frequency at the operating speed of the motor 71. Under this condition the amplitude of vibration is increased by resonance so that a four or five fold increase in force is obtained over what would be obtained in a non-resonant system having the same unbalanced weights 7 3.

In order to minimize the use of flexible tubing in the construction of the assembly the compressed air is taken from the control box 61 to the expansible chamber 37 by way of a line 75 which can be rigidly attached to the frame 25 since it passes along the top of the frame and down between an end portion of the frame and an i adjacent plate 33 of the frame 25 against which the chamber 37 operates. Likewise air lines 76 and 77 leading from the control box 61 to the expansible chambers 55 and 56 may be rigidly attached to the frame 25.

The air lines 76 and 77, as shown in FIG. VI, are preferably provided with restrictions 78 and 79 to minimize circulation of air between the chambers 55 and 56 as they are subjected to the vibration of the exciter member 59. The circulation of air through these connections 76 and 77, if permitted, provides a detuning and damping effect that seriously limits the obtainable amplitude of vibration of the system.

This arrangement of an exciter member that coopcrates with adjustable resilient elements makes possible a car vibrator unit which is not only light in weight so as to be easily maneuverable into position but which also is capable of supplying extremely large vibratory forces as may be required to accelerate the discharge of material from the hopper or car.

Various modifications of the structure may be made without departing from the spirit and scope of the invention.

Having described the invention, I claim:

1. A vibrator for accelerating the discharge from a container comprising, in combination, a first member having means including fiat surfaced jaws for clamping it to the container, a second member, a prime mover including a rotatable shaft carrying an eccentric weight mounted in the second member, means mounting the second member from the first for movement along a line normal to and passing through said flat surfaced jaws, and a plurality of gas filled expansible chambers connected between said first and second members and cooperating with said members to form a vibratory system, said gas filled chambers being inflated to a pressure such that the vibratory system with the first member clamped to the container is resonant at a frequency generally equal to the speed of rotation of the eccentric weight.

2. A vibrator for accelerating the discharge from a container comprising, in combination, a first member having means including flat surfaced jaws for clamping it to the container to be discharged, :1 second member, an eccentrically loaded shaft journalled in the second member, means for rotating the shaft at a generally constant speed, means mounting the second member in the first member for movement toward and from the container along a line normal to and passing through said flat surfaced jaws, and a plurality of inflatable expansible chambers connected between said members, said chambers having flexible side walls and being inflated to a pressure such that said chambers and said members form a resonant vibratory system having a natural frequency approximately equal to the speed of rotation of said shaft when the first member is clamped to the container.

3. A vibrator for accelerating the discharge from a container comprising, in combination, a frame having a face adapted to abut a surface of the container, a yoke slidably mounted on the frame and having a jaw cooperating with the face of the frame to form a clamp to hold the frame to the container, means for sliding the yoke to clamping position, a vibration exciter mounted on the frame for reciprocation of its center of mass along a line normal to and passing through the surface of the container engaged by said jaw and face, an eccentric weight journalled in the exciter, means for driving the weight at a substantially constant speed, and a plurality of expansible chambers connected between said exciter and frame and cooperating with said exciter and frame to form a vibratory system, said chambers having flexible side walls and being inflated to a pressure such that resonant vibration of the vibratory system occurs at a frequency equal to the speed of the shaft when said frame is clamped to the container.

4. A vibrator for accelerating the discharge from a container comprising, in combination, a first member having a pair of spaced parallel side rails joined at one end by a cross member including a clamp jaw and at the other end by a cross member forming an abutment, a second member that is slidably mounted on said side rails and that has a surface forming a second clamp jaw opposed to the first, an expansible chamber inserted between the second member and the abutment of the first member for forcing the second member toward the clamp jaw, an exciter mounted in the second member for movement of its center of mass along a line generally parallel to the side rails and passing through said clamp jaw, a prime mover including rotatable eccentric weights rigidly mounted in the exciter member, and a plurality of gas filled expansible chambers coupling the exciter member to the second member, said gas filled chambers being References Cited in the file of this patent UNITED STATES PATENTS 2,229,037 Boldman Jan. 21, 1941 2,406,403 Rogers Aug. 27, 1946 2,445,175 Hittson July 3, 1948 2,560,480 Rogers et al. July 10, 1951 2,636,719 OConner Apr. 28, 1953 2,706,566 Friedh et al Apr. 19, 1955 2,840,251 Roubal June 24, 1958 2,853,199 Plant Sept. 23, 1958 2,984,339 Musschoot May 6, 1961 

1. A VIBRATOR FOR ACCELERATING THE DISCHARGE FROM A CONTAINER COMPRISING, IN COMBINATION, A FIRST MEMBER HAVING MEANS INCLUDING FLAT SURFACED JAWS FOR CLAMPING IT TO THE CONTAINER, A SECOND MEMBER, A PRIME MOVER INCLUDING A ROTATABLE SHAFT CARRYING AN ECCENTRIC WEIGHT MOUNTED IN THE SECOND MEMBER, MEANS MOUNTING THE SECOND MEMBER FROM THE FIRST FOR MOVEMENT ALONG A LINE NORMAL TO AND PASSING THROUGH SAID FLAT SURFACED JAWS, AND A PLURALITY OF GAS FILLED EXPANSIBLE CHAMBERS CONNECTED BETWEEN SAID FIRST AND SECOND MEMBERS AND COOPERATING WITH SAID MEMBERS TO FORM A VIBRATORY SYSTEM, SAID GAS FILLED CHAMBERS BEING INFLATED TO A PRESSURE SUCH THAT THE VIBRATORY SYSTEM WITH THE FIRST MEMBER CLAMPED TO THE CONTAINER IS RESONANT AT A FREQUENCY GENERALLY EQUAL TO THE SPEED OF ROTATION OF THE ECCENTRIC WEIGHT. 